Tanat Valley 3 by Peter Drost
A simple turnout operating unit by Alan Clark
At Telford in 1999, I was talking with the late Peter Turville about operating the switch blades on S7 turnouts. He suggested using cast stretcher bar blade fixings (sold by S7 Stores) and copperclad fibreglass strips (sold by C&L) with hinged switch blades and a single central connection (on the stretcher bar) from the point motor.
Personally I wanted to use a mechanical system with MSE lever frames and aeromodelling rods and cranks (under the baseboard). Therefore, I would have to design and build the Turnout Operating Unit (TOU) to suit my preferred system.
When working in P4, many years ago, I used the original Studiolith TOUs which always struck me as being an elegantly simple design. This used a combination of curtain rod tracks, solid perspex sections, and tubes from syringes. Obtaining these components did not seem easy to me, so I kept my eyes open for some alternatives.
What I have ended up with on my own S7 layout is a simple, easy to build, TOU design (using readily available components) based on the original Studiolith principle. I think the photographs clearly show the component parts and the completed units.
Component parts of TOU
Two sizes of square ABS plastic tube, one of which is free to slide within the other. L-shaped ABS plastic sections, attached to either side of the outer tube, for mounting support under the baseboard. Nickel silver wire (0.7mm) which fits inside a brass tube.
Installed TOUs
Small piece of brass tube soldered to copperclad fibreglass strip. Operating wire (fitted in brass tube mounted in the sliding section of the square section ABS plastic tube in the TOU) connects with this small piece of tube.
